<!DOCTYPE html>
<html>
<head2>
<meta charset="UTF-8">
<title>Insert title here</title>
<script src="js/jquery.js"></script>
</head>
<body>
 <a href="javascript:;" id="test">点击</a>
</body>
<script type="text/javascript">
$("#test").on("click",function(){
	$.ajax({
		type:"GET",
		url:"HelloWorld.do",
		data:null,
		contentType:"application/x-www-form-urlencoded; charset=utf-8", 
		async:true,
		dataType:'text',
		traditional:true,
		error: function(data,transport){
			debugger;
		},
		success:function(msg){
			 alert(msg);
		}
	});
});

</script>
</html>